This invention relates to the control of atmospheres around respiring biological materials.
Respiring biological materials, e.g., fruits and vegetables, consume oxygen (O2) and produce carbon dioxide (CO2) at rates which depend upon the stage of their development, the atmosphere surrounding them and the temperature. In modified atmosphere packaging (MAP), the respiring materials are surrounded by a packaging atmosphere in a sealed container and the packaging atmosphere is controlled by providing an atmosphere control member (ACM) which (a) has one surface in contact with the packaging atmosphere and an opposite surface in contact with an external atmosphere and (b) has a permeability to O2 and CO2 such that gas exchange of O2 and CO2 through the ACM produces the desired packaging atmosphere. In controlled atmosphere packaging (CAP), by contrast, the desired packaging atmosphere is produced, initially and/or on a continuous or discontinuous program, simply by displacing some or all of the atmosphere within a sealed container by one or more gases, e.g., nitrogen, O2 and CO2, in desired proportions.
For further details of MAP and CAP, reference may be made, for example, to U.S. Pat. No. 3,360,380 (Bedrosian), U.S. Pat. No. 3,450,542 (Badran), U.S. Pat. No. 3,450,544 (Badran et al.), U.S. Pat. No. 3,798,333 (Cummin et al), U.S. Pat. No. 3,924,010 (Erb), U.S. Pat. No. 4,003,728 (Rath), U.S. Pat. No. 4,734,324 (Hill), U.S. Pat. No. 4,779,524 (Wade), U.S. Pat. No. 4,830,863 (Jones), U.S. Pat. No. 4,842,875 (Anderson), U.S. Pat. No. 4,879,078 (Antoon), U.S. Pat. No. 4,910,032 (Antoon), U.S. Pat. No. 4,923,703 (Antoon), U.S. Pat. No. 4,987,745 (Harris), U.S. Pat. No. 5,041,290 (Wallace et al.) U.S. Pat. No. 5,045,331 (Antoon), U.S. Pat. No. 5,063,753 (Woodruff), U.S. Pat. No. 5,160,768 (Antoon), U.S. Pat. No. 5,254,354 (Stewart), U.S. Pat. No. 5,333,394 (Herdeman), U.S. Pat. No. 5,433,335 (Raudalus et al.), U.S. Pat. No. 5,443,851 (Christie et al.), U.S. Pat. No. 5,460,841 (Herdeman), U.S. Pat. No. 5,556,658 (Raudalus et al.), U.S. Pat. No. 5,658,607 (Herdeman), U.S. Pat. No. 5,807,630 (Christie et al.), U.S. Pat. No. 5,832,699 (Zobel), U.S. Pat. No. 5,872,721 (Huston et al.), U.S. Pat. No. 6,013,293 (De Moor), U.S. Pat. No. 6,190,710 (Nir et al), U.S. Pat. No. 6,210,724 (Clarke et al.), U.S. Pat. No. 6,296,923 (Zobel), U.S. Pat. No. 6,376,032 (Clarke et al.), U.S. Pat. No. 6,548,132 (Clarke et al.), U.S. Pat. No. 7,329,452 (Clarke), U.S. Pat. No. 7,601,202 (Noack et al), U.S. Pat. No. 7,601,374 (Clarke), U.S. Pat. No. 7,801,374 (Clarke), U.S. Pat. No. 7,866,258 (Jorgensen), and U.S. Pat. No. 8,177,883 (Maersk); copending commonly assigned U.S. application Ser. No. 09/580,379 (Clarke) and U.S. Ser. No. 09/858,190 (Clarke); US Patent Application Publication Nos. 2003/0057217 (Wyslotsky), 2005/0266129 (Mir), 2007/0259082 (Clarke et al.), 2008/0008793 and 2008/0008794 (Forsyth et al.), 2008/0202262 (Schmidt et al.), and 2011/0293802 (Alfaro et al.); International Publication Nos. WO 94/12040 (Fresh Western), WO 96/38495 (Landec), WO 00/04787 (Landec), WO 01/92118 (Landec), WO 03/043447 (Landec), WO 2004/060538 (Blue Membranes), WO 2004/10868 (Maersk), WO 2005/074466 (Landec) and WO 2008/17307 (Maersk); and European Applications Nos. 0,351,115 and 0,351,116 (Courtaulds). The disclosure of each of those patents, applications and publications is incorporated herein by reference in their entirety for all purposes.